Investigation on thermal reliability and optimisation design for high-power LED micro/nano system

Abstract

To optimise the overall structural design of high-power LED and to effectively improve thermal dissipation, we analyse the thermal structure of high-power LED. Firstly, the thermal problems of high-power LED are described in detail. A complete thermal model is established based on finite element method. Secondly, numerical simulations on the theoretical analysis of LED system are made. The results show that there are three aspects in this part of the thermal resistance. The thermal dissipation of LED could be increased and then the LED junction temperature is also controlled within a certain range. Secondly, we investigate the factors which mainly influence heat dissipation. Meanwhile, we simulate the relationships between the temperature of LED chip and the height h of the radiator, the radius R of the radiator and the radius r of LED lamp posts, respectively. The results show clearly the effects of various factors on the temperature of LED chip. Meanwhile, without affecting the structures of the radiator and ED lamp posts, the optimal values of each single factor are found. The results reveal the thermal field mechanism of LED system, which is very helpful for design and manufacturing of LED assembly.